ldd: separate Parse from Exec and trim space

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

4 files changed, 139 insertions, 28 deletions

diff --git a/ldd/error.go b/ldd/error.go
index 51aef948..39b63ef9 100644
--- a/ldd/error.go
+++ b/ldd/error.go
@@ -1,11 +1,27 @@
 package ldd
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+)
 
-type EntryUnexpectedSegmentsError struct {
-	Entry string
+var (
+	ErrUnexpectedSeparator = errors.New("unexpected separator")
+	ErrPathNotAbsolute     = errors.New("path not absolute")
+	ErrBadLocationFormat   = errors.New("bad location format")
+	ErrUnexpectedNewline   = errors.New("unexpected newline")
+)
+
+type EntryUnexpectedSegmentsError string
+
+func (e EntryUnexpectedSegmentsError) Is(err error) bool {
+	var eq EntryUnexpectedSegmentsError
+	if !errors.As(err, &eq) {
+		return false
+	}
+	return e == eq
 }
 
-func (e *EntryUnexpectedSegmentsError) Error() string {
-	return fmt.Sprintf("unexpected segments in entry %q", e.Entry)
+func (e EntryUnexpectedSegmentsError) Error() string {
+	return fmt.Sprintf("unexpected segments in entry %q", string(e))
 }
diff --git a/ldd/exec.go b/ldd/exec.go
new file mode 100644
index 00000000..d6a2af58
--- /dev/null
+++ b/ldd/exec.go
@@ -0,0 +1,18 @@
+package ldd
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+func Exec(p string) ([]*Entry, error) {
+	t := exec.Command("ldd", p)
+	t.Stdout, t.Stderr = new(strings.Builder), os.Stderr
+	if err := t.Run(); err != nil {
+		return nil, err
+	}
+
+	return Parse(t.Stdout.(fmt.Stringer))
+}
diff --git a/ldd/ldd.go b/ldd/ldd.go
index 989aeca5..6c2aec30 100644
--- a/ldd/ldd.go
+++ b/ldd/ldd.go
@@ -1,49 +1,31 @@
 package ldd
 
 import (
-	"errors"
 	"fmt"
 	"math"
-	"os"
-	"os/exec"
 	"path"
 	"strconv"
 	"strings"
 )
 
-var (
-	ErrUnexpectedSeparator = errors.New("unexpected separator")
-	ErrPathNotAbsolute     = errors.New("path not absolute")
-	ErrBadLocationFormat   = errors.New("bad location format")
-)
-
 type Entry struct {
 	Name     string `json:"name,omitempty"`
 	Path     string `json:"path,omitempty"`
 	Location uint64 `json:"location"`
 }
 
-func Exec(p string) ([]*Entry, error) {
-	t := exec.Command("ldd", p)
-	t.Stdout = new(strings.Builder)
-	t.Stderr = os.Stderr
-
-	if err := t.Run(); err != nil {
-		return nil, err
-	}
-
-	out := t.Stdout.(fmt.Stringer).String()
-	payload := strings.Split(out, "\n")
-
+func Parse(stdout fmt.Stringer) ([]*Entry, error) {
+	payload := strings.Split(strings.TrimSpace(stdout.String()), "\n")
 	result := make([]*Entry, len(payload))
 
 	for i, ent := range payload {
 		if len(ent) == 0 {
-			continue
+			return nil, ErrUnexpectedNewline
 		}
 
 		segment := strings.SplitN(ent, " ", 5)
 
+		// location index
 		var iL int
 
 		switch len(segment) {
@@ -63,7 +45,7 @@ func Exec(p string) ([]*Entry, error) {
 				Path: segment[2],
 			}
 		default:
-			return nil, &EntryUnexpectedSegmentsError{ent}
+			return nil, EntryUnexpectedSegmentsError(ent)
 		}
 
 		if loc, err := parseLocation(segment[iL]); err != nil {
diff --git a/ldd/ldd_test.go b/ldd/ldd_test.go
new file mode 100644
index 00000000..ec8a5d0c
--- /dev/null
+++ b/ldd/ldd_test.go
@@ -0,0 +1,95 @@
+package ldd_test
+
+import (
+	"errors"
+	"reflect"
+	"strings"
+	"testing"
+
+	"git.ophivana.moe/cat/fortify/ldd"
+)
+
+func TestParseError(t *testing.T) {
+	testCases := []struct {
+		name, out string
+		wantErr   error
+	}{
+		{"unexpected newline", `
+/lib/ld-musl-x86_64.so.1 (0x7ff71c0a4000)
+
+libzstd.so.1 => /usr/lib/libzstd.so.1 (0x7ff71bfd2000)
+`, ldd.ErrUnexpectedNewline},
+		{"unexpected separator", `
+libzstd.so.1 = /usr/lib/libzstd.so.1 (0x7ff71bfd2000)
+`, ldd.ErrUnexpectedSeparator},
+		{"path not absolute", `
+libzstd.so.1 => usr/lib/libzstd.so.1 (0x7ff71bfd2000)
+`, ldd.ErrPathNotAbsolute},
+		{"unexpected segments", `
+meow libzstd.so.1 => /usr/lib/libzstd.so.1 (0x7ff71bfd2000)
+`, ldd.EntryUnexpectedSegmentsError("meow libzstd.so.1 => /usr/lib/libzstd.so.1 (0x7ff71bfd2000)")},
+		{"bad location format", `
+libzstd.so.1 => /usr/lib/libzstd.so.1 7ff71bfd2000
+`, ldd.ErrBadLocationFormat},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			stdout := new(strings.Builder)
+			stdout.WriteString(tc.out)
+
+			if _, err := ldd.Parse(stdout); !errors.Is(err, tc.wantErr) {
+				t.Errorf("Parse() error = %v, wantErr %v", err, tc.wantErr)
+			}
+		})
+	}
+}
+
+func TestParse(t *testing.T) {
+	testCases := []struct {
+		file, out string
+		want      []*ldd.Entry
+	}{
+		{"musl /bin/kmod", `
+/lib/ld-musl-x86_64.so.1 (0x7ff71c0a4000)
+libzstd.so.1 => /usr/lib/libzstd.so.1 (0x7ff71bfd2000)
+liblzma.so.5 => /usr/lib/liblzma.so.5 (0x7ff71bf9a000)
+libz.so.1 => /lib/libz.so.1 (0x7ff71bf80000)
+libcrypto.so.3 => /lib/libcrypto.so.3 (0x7ff71ba00000)
+libc.musl-x86_64.so.1 => /lib/ld-musl-x86_64.so.1 (0x7ff71c0a4000)`,
+			[]*ldd.Entry{
+				{"/lib/ld-musl-x86_64.so.1", "", 0x7ff71c0a4000},
+				{"libzstd.so.1", "/usr/lib/libzstd.so.1", 0x7ff71bfd2000},
+				{"liblzma.so.5", "/usr/lib/liblzma.so.5", 0x7ff71bf9a000},
+				{"libz.so.1", "/lib/libz.so.1", 0x7ff71bf80000},
+				{"libcrypto.so.3", "/lib/libcrypto.so.3", 0x7ff71ba00000},
+				{"libc.musl-x86_64.so.1", "/lib/ld-musl-x86_64.so.1", 0x7ff71c0a4000},
+			}},
+		{"glibc /nix/store/rc3n2r3nffpib2gqpxlkjx36frw6n34z-kmod-31/bin/kmod", `
+linux-vdso.so.1 (0x00007ffed65be000)
+libzstd.so.1 => /nix/store/80pxmvb9q43kh9rkjagc4h41vf6dh1y6-zstd-1.5.6/lib/libzstd.so.1 (0x00007f3199cd1000)
+liblzma.so.5 => /nix/store/g78jna1i5qhh8gqs4mr64648f0szqgw4-xz-5.4.7/lib/liblzma.so.5 (0x00007f3199ca2000)
+libc.so.6 => /nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib/libc.so.6 (0x00007f3199ab5000)
+libpthread.so.0 => /nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib/libpthread.so.0 (0x00007f3199ab0000)
+/nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib/ld-linux-x86-64.so.2 => /nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib64/ld-linux-x86-64.so.2 (0x00007f3199da5000)`,
+			[]*ldd.Entry{
+				{"linux-vdso.so.1", "", 0x00007ffed65be000},
+				{"libzstd.so.1", "/nix/store/80pxmvb9q43kh9rkjagc4h41vf6dh1y6-zstd-1.5.6/lib/libzstd.so.1", 0x00007f3199cd1000},
+				{"liblzma.so.5", "/nix/store/g78jna1i5qhh8gqs4mr64648f0szqgw4-xz-5.4.7/lib/liblzma.so.5", 0x00007f3199ca2000},
+				{"libc.so.6", "/nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib/libc.so.6", 0x00007f3199ab5000},
+				{"libpthread.so.0", "/nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib/libpthread.so.0", 0x00007f3199ab0000},
+				{"/nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib/ld-linux-x86-64.so.2", "/nix/store/c10zhkbp6jmyh0xc5kd123ga8yy2p4hk-glibc-2.39-52/lib64/ld-linux-x86-64.so.2", 0x00007f3199da5000},
+			}},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.file, func(t *testing.T) {
+			stdout := new(strings.Builder)
+			stdout.WriteString(tc.out)
+
+			if got, err := ldd.Parse(stdout); err != nil {
+				t.Errorf("Parse() error = %v", err)
+			} else if !reflect.DeepEqual(got, tc.want) {
+				t.Errorf("Parse() got = %#v, want %#v", got, tc.want)
+			}
+		})
+	}
+}